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solar panels on foamie roof?

PostPosted: Tue Nov 10, 2020 8:22 pm
by Noc3
Hi,
I'm new here, currently working on a 10.5' x 5.5' x 5' foamie squaredrop.

The floor and drop floor are done. I'm about to get to the foam construction. Due to the size of the design I'm edge gluing foam panels and plan on using a channel cut along the edge joints to form tongue and groove that will lap over the edges of both foam pieces, add some additional support and give me something to screw into.

As for the solar panels they are roughly 64"x34" and 42lbs each. So I think I'm going to run a plywood beam along each outside edge of the camper inset on a channel cut on the outer edge of the roof piece. Again just for something hard to screw to and for the railing to sit on.

The walls are just 2" foam/pmf. No wood for vertical supports in the plan, just the vertical walls at the front and back.

I guess I do have some concerns about how the points where the roof will be penetrated will hold up to water and potential wear at the points where the roof rack contacts the roof.

Any pointers?

Re: solar panels on foamie roof?

PostPosted: Tue Nov 10, 2020 9:35 pm
by linuxmanxxx
You'd be surprised how much strength just adding a little wood hard points will give you as well as something to mount to. Maybe a few vertical cedar strips would help support the panel weight and still be light and rot resistant. Solar panels aren't light from what I've dealt with.
Steve

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Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 1:12 pm
by John61CT
Don't bother with the "semi flexible" panels, aluminum framed rigid type are heavier but last a lot longer.

Personally I would do a metal exo frame to hold a roof rack, and a foamie shell that slides within

Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 1:54 pm
by linuxmanxxx
John61CT wrote:Don't bother with the "semi flexible" panels, aluminum framed rigid type are heavier but last a lot longer.

Personally I would do a metal exo frame to hold a roof rack, and a foamie shell that slides within
Plus 1 or any kind of hard frame to support the panels. Time heat and weight are against you if the support is marginal.
Steve

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Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 2:11 pm
by Noc3
John61CT wrote:Don't bother with the "semi flexible" panels, aluminum framed rigid type are heavier but last a lot longer.

Personally I would do a metal exo frame to hold a roof rack, and a foamie shell that slides within



You know the idea crossed my mind...And is still on the table. I was thinking 1.5" angle iron, four supports vertically on edge welded to frame mounts then bolted to trailer frame. All four vertical rails connected at top by rectangular box of angle for the roof rack.

I was hoping to be done with welding on the project though. Perhaps I can do it by welding only a few crucial parts and bolting the rest.

Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 2:36 pm
by linuxmanxxx
If your worried about weight use aluminum it's vastly lighter than steel.

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Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 3:57 pm
by Terra6
I've had 4 40x80 solar panels up on my roof for 2 yrs now.
75 mph hwy and 40 plus mph winds. :NC
Inset cedar fence boards into my roof with PL3, covered with pmf. Used heavy duty construction corner braces with lag screws to roof and self tapping screws through solar panel aluminum frame. No roof rack required. Works for me. :thumbsup:
But my walls are 4inch EPS with vertical reinforcements every 4ft.
As for leakage, sealed with asphalt flashing +silicon under screws and braces, but I'm in the dry southwest.
And I recommend not watering your roof if at all possible. :lol:
As for wear, no issues the way I've done it, so far.
90 degree brackets are solidly mounted with 3 on each end of my 50lb panels. Plus 4 on the front leading edge of the first panel.

Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 6:26 pm
by Terra6
This is the corner brace that i used fyi

Simpson strong tie 2x2x4 12ga L bracket

https://www.whitecap.com/globalassets/i ... &width=470

Re: solar panels on foamie roof?

PostPosted: Wed Nov 11, 2020 6:50 pm
by Noc3
aluminum is way more expensive than steel and harder to weld. Its also more flexible and in this application I want rigidity in a low profile.

I like the idea of a sturdy roof rack I can have the panels mounted on with releasable hinges to tilt them to either side, or to be able to take them off the roof and move them out of the shade. Another option with this setup would be to mount panels to the frame on legs allowing for some roof storage underneath the panels.

I live in the southern part of the blue ridge mountains where its very moist and just a few annual inches short of being a temperate rainforest. Penetrating the roof in any way is not something I really want to do. I will likely run wires thru conduit over the leading edge of the roof, down the front and penetrate under the floor.

I also install solar professionally on houses for my day job. FWIW.